Conventional elastic cords, such as bungee cords, usually consist of one or more natural or artificial rubber strings surrounded by a woven jacket. The woven jacket, made of nylon or other similar materials, is made of threads woven in a tubular form and are elongated or contracted with the core member. Elastic cords are used for trailer, car, and bike tie downs, trampolines, and numerous other application. However, the versatility, durability, and performance of conventional cords are limited by its construction and design, which is improved by this invention.
There are many structural disadvantages of conventional cords. Generally, the rubber stings comprising the core of conventional elastic cords are wider than they are thick, thus when the strings are stretched the width of the strings becomes noticeably more distorted than does the thickness. As the cord is elongated the core member grows slimmer, yet the woven fabric remains the same thickness, thus creating a gap between the core and the jacket. Over time, this gap results in irregular shifting of the rubber strings; eventually, continuous use may lead to fatigue and premature failure or breakage of the cord. Moreover, the strength and design of the conventional elastic cord is limited to the number of rubber strings used for the core. Thus, in order to build a stronger cord, the diameter of the elastic cord must be increased by using more rubber strings for the core, thereby increasing the diameter of the cord. Furthermore, because the rubber strings of conventional elastic cord are densely packed together, it has limited flexibility and malleability and cannot be easily knotted. In addition, its dense structure can be harsh on any objects being tied down.